Cooperative treatment system for multiple pollutants in flue gas of heating furnace
By installing desulfurization, CO removal, and flue gas mixing devices in the regenerative steel rolling furnace, the problems of explosion risk and high energy consumption caused by high CO concentration have been solved, achieving efficient flue gas treatment and reducing equipment investment and operating costs.
Patent Information
- Application Number
- CN202423276648.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-12-27
- Filing Date
- 2024-12-30
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-30
AI Technical Summary
The high CO concentration in the flue gas of regenerative steel rolling furnaces poses an explosion risk and causes environmental pollution. Existing technologies are energy-intensive, have complex equipment, and require a large footprint. Furthermore, CO catalysts are prone to poisoning and deactivation.
The system employs first and second desulfurization units, a CO removal unit, a flue gas mixing unit, and an SCR denitrification unit to desulfurize, remove CO, and mix the coal smoke and air flue gas before heating them. This reduces energy consumption and meets the denitrification temperature requirements. Only one SCR denitrification unit is needed. Dust removal and ammonia injection units are added to improve system stability and heat recovery.
It eliminates CO emissions and explosion risks, reduces energy consumption, reduces equipment investment and land occupation, and improves system stability and heat recovery efficiency.
Smart Images
Figure CN223580670U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the industrial flue gas purification technology, and particularly relates to a heating furnace flue gas multi-pollutant collaborative treatment system. BACKGROUND
[0002] The regenerative steel rolling heating furnace is widely used because of the low calorific value fuel and good energy saving effect. During the combustion reversing, the gas in the pipeline between the gas nozzle and the reversing valve is directly discharged into the flue gas of the coal smoke side, and the air in the pipeline between the combustion air nozzle and the reversing valve is directly discharged into the flue gas of the empty smoke side, so that the flue gas of the coal smoke side of the heating furnace contains 30,000-50,000 ppm CO, and the oxygen concentration of the empty smoke side is high. If the coal smoke and the empty smoke are mixed, the explosion risk may occur. Therefore, the tail flue gas of the regenerative heating furnace must be independently discharged for the coal smoke flue gas and the empty smoke flue gas. Meanwhile, the emission of a large amount of CO also causes serious pollution to the environment.
[0003] With the continuous improvement of the steel environmental protection index, the steel rolling heating furnace also faces the requirement of realizing ultra-low emission of desulfurization and denitrification. Because the exhaust gas temperature of the regenerative steel rolling heating furnace is low, and the empty smoke and the coal smoke are independently discharged, the desulfurization and denitrification also need one set for the empty smoke and the coal smoke, and the gas-gas heater (GGH), the flue gas heating and temperature rising device and the like need to be configured. The overall treatment process is complex, the energy consumption is high, the investment is large, and the land occupation is large.
[0004] The prior art discloses a heating furnace desulfurization and denitrification collaborative carbon monoxide removal system, which comprises a heating furnace; the heating furnace is respectively provided with a coal smoke gas outlet and an empty smoke gas outlet; the coal smoke gas outlet and the empty smoke gas outlet are respectively connected with a flue gas treatment assembly; the flue gas treatment assembly comprises a desulfurization treatment reactor, a heating heat exchanger, a denitrification reducing agent, a denitrification and decarburization reactor, a flue gas induced draft fan and a chimney which are sequentially communicated; and the heating heat exchanger is connected with a gas heating device. Therefore, the coal smoke flue gas and the empty smoke flue gas can be respectively subjected to the desulfurization and denitrification collaborative carbon monoxide removal treatment, the problem of flammability and explosion after the mixture of the coal smoke flue gas and the empty smoke flue gas is avoided, and the removal treatment of carbon monoxide is considered. The amount of carbon monoxide emission is reduced, the gas consumption of the heating device and the use of the denitrification reducing agent are reduced, and the carbon emission is reduced.
[0005] The above technical scheme is to set the CO catalyst after the fixed bed desulfurization and dust removal, to catalytically oxidize the CO in the flue gas into CO2, so as to heat the flue gas, but the GGH heat exchanger, the secondary heat exchanger, the heating furnace, the SCR denitrification system, the chimney and the induced draft fan are still provided with two sets, and the energy consumption is large. Meanwhile, the ammonia injection device is provided before the CO catalyst, the CO catalyst is easily poisoned by ammonia, the CO catalyst is deactivated in a short time, and the heating function cannot be achieved. Practical new type content
[0006] In order to solve the above problem of large energy consumption, the application provides a heating furnace flue gas multi-pollutant collaborative treatment system.
[0007] The application provides a heating furnace flue gas multi-pollutant collaborative treatment system, which adopts the following technical scheme:
[0008] The heating furnace flue gas multi-pollutant collaborative treatment system comprises a first desulfurization device, a second desulfurization device, a CO removal device, a flue gas mixing device and an SCR denitration device, wherein the first desulfurization device, the CO removal device, the flue gas mixing device and the SCR denitration device are sequentially connected by pipelines along the flow direction of the coal smoke flue gas.
[0009] By adopting the above technical scheme, the coal smoke flue gas is treated by the first desulfurization device and the CO removal device, and the CO is removed, so that the CO in the coal smoke flue gas is eliminated, the CO emission problem and the risk of explosion are solved. The coal smoke flue gas is heated due to the heat released in the CO removal process, and then is mixed with the desulfurized air smoke flue gas in the flue gas mixing device. After mixing, the overall temperature of the flue gas is also increased, which can meet or partially meet the temperature required for subsequent denitration, thereby reducing the problem that a large amount of energy is consumed to heat the flue gas for denitration in the prior art, and reducing the operating cost. After the coal smoke flue gas and the air smoke flue gas are mixed in the flue gas mixing device, only one set of SCR denitration device needs to be arranged, which can save the operating cost and large equipment investment compared with the prior art, and the occupied area is reduced.
[0010] Preferably, the first dust removal device and the second dust removal device are further included, the first dust removal device is arranged between the first desulfurization device and the CO removal device, and the first desulfurization device, the first dust removal device and the CO removal device are sequentially connected by pipelines; and the second dust removal device is arranged between the second desulfurization device and the flue gas mixing device, and the second desulfurization device, the second dust removal device and the flue gas mixing device are sequentially connected by pipelines.
[0011] By adopting the above technical scheme, as a specific structural example, the first dust removal device and the second dust removal device are additionally arranged, and the coal smoke flue gas and the air smoke flue gas are sequentially subjected to dust removal treatment, so that the influence of dust on CO removal and denitration is reduced, and the stability and service life of the overall system are improved.
[0012] Preferably, the first dust removal device and the second dust removal device are respectively bag dust collectors.
[0013] By adopting the technical scheme, as a specific structural example, the first dust removal device and the second dust removal device are both selected as the existing bag-type dust collector, and the model thereof is determined according to the actual demand function and parameter requirement.
[0014] Preferably, the ammonia injection device is arranged between the flue gas mixing device and the SCR denitration device, and the flue gas mixing device, the ammonia injection device and the SCR denitration device are sequentially connected by pipelines.
[0015] By adopting the technical scheme, as a structural example, the ammonia injection device is additionally arranged between the flue gas mixing device and the SCR denitration device, so as to reduce the influence of ammonia on the catalyst and meet the needs of subsequent denitration.
[0016] Preferably, the waste heat recovery device is additionally arranged between the flue gas mixing device and the SCR denitration device.
[0017] By adopting the technical scheme, as a structural example, the waste heat recovery device is additionally arranged to recover the heat energy of the flue gas treated by the SCR denitration device.
[0018] Preferably, the waste heat recovery device is a steam generator.
[0019] By adopting the technical scheme, as a structural example, the waste heat recovery device can be selected as a common steam generator, and the flue gas passes through the steam generator to generate low-pressure steam or hot water, thereby realizing heat energy recovery.
[0020] Preferably, the waste heat recovery device is additionally arranged between the flue gas mixing device and the SCR denitration device.
[0021] By adopting the technical scheme, as a structural example, the flue gas treated by the SCR denitration device sequentially passes through the induced draft fan and the chimney and is finally discharged to the outside, and when the waste heat recovery device is additionally arranged, the flue gas recovered by the waste heat recovery device is discharged to the outside.
[0022] Preferably, the first desulfurization device and the second desulfurization device are both selected as the common semi-dry desulfurization tower.
[0023] By adopting the technical scheme, as a structural example, the first desulfurization device and the second desulfurization device are both selected as the common semi-dry desulfurization tower.
[0024] In summary, the present application has at least the following beneficial effects:
[0025] (1) The heating furnace flue gas multi-pollutant collaborative treatment system of the application eliminates CO in coal smoke flue gas, solves the problem of CO emission and the risk of explosion.
[0026] (2) The coal smoke flue gas is heated due to the heat released in the CO removal process, and then mixed with the desulfurized flue gas in a flue gas mixing device. After mixing, the overall temperature of the flue gas will also rise, which can meet or partially meet the temperature required for subsequent denitrification, reducing the problem of a large amount of energy required for flue gas heating for denitrification in the prior art, and reducing operating costs.
[0027] (3) Only one set of SCR denitrification device needs to be set, which can save operating costs and large equipment investment compared with the prior art, and the land occupation is reduced. BRIEF DESCRIPTION OF DRAWINGS
[0028] Figure 1 is a structural schematic diagram of the heating furnace flue gas multi-pollutant collaborative treatment system of the embodiment of the application.
[0029] REFERENCE NUMERALS:
[0030] 11, first desulfurization device; 12, second desulfurization device; 2, CO removal device; 3, flue gas mixing device; 4, SCR denitrification device; 51, first dust removal device; 52, second dust removal device; 6, ammonia injection device; 7, waste heat recovery device; 8, induced draft device; 9, chimney. DETAILED DESCRIPTION
[0031] Although the present application can be easily embodied in different forms of embodiments, only some specific embodiments thereof are shown in the drawings and will be described in detail in the present specification, and it can be understood that the present specification should be considered as a demonstrative description of the principles of the present application, and is not intended to limit the present application to what is described herein.
[0032] Therefore, one feature indicated in the present specification will be used to explain one feature of one embodiment of the present application, and it is not implied that each embodiment of the present application must have the explained feature. In addition, it should be noted that the present specification describes many features. Although certain features can be combined together to show possible system designs, these features can also be used in other combinations not explicitly described. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.
[0033] In the embodiments shown in the drawings, the indications of directions such as up, down, left, right, front and back are used to explain the structure and movement of various elements of the present application, which are not absolute but relative. When these elements are in the positions shown in the drawings, these indications are appropriate. If the positions of these elements change, the indications of directions also change accordingly.
[0034] The present application is further described in detail below with reference to the accompanying drawings and examples.
[0035] Word explanation:
[0036] SCR: is the abbreviation of Selective Catalytic Reduction, which means selective catalytic reduction.
[0037] Coal soot flue gas / empty soot flue gas: the flue gas discharged from the regenerative heating furnace is divided into two ways to heat exchange with coal gas and air respectively, and the exchanged flue gas corresponds to coal soot flue gas and empty soot flue gas in turn. Because of the use of regenerative heating method, the flue gas discharged after heat exchange with coal gas contains high concentration of CO, and the flue gas exchanged with air contains high oxygen content.
[0038] Example 1
[0039] According to one embodiment shown in the present embodiment, see Figure 1 , throughout the view, the same reference signs represent corresponding parts. It should be understood that the heating furnace flue gas multi-pollutant co-processing system according to the present application can be used in the treatment of flue gas discharged from all regenerative heating furnaces.
[0040] As shown in Figure 1 , the heating furnace flue gas multi-pollutant co-processing system of the present embodiment comprises: a first desulfurization device, a second desulfurization device, a CO removal device, a flue gas mixing device, an SCR denitration device, a first dust removal device, a second dust removal device, an ammonia injection device, a waste heat recovery device, an induced draft device and a chimney.
[0041] In the present embodiment, the CO removal device is a CO catalytic oxidation reactor, the induced draft device is an induced draft fan, the ammonia injection device is an ammonia injection grid, the waste heat recovery device is a steam generator (i.e. a boiler), the first dust removal device and the second dust removal device are both bag dust collectors, and the first desulfurization device and the second desulfurization device are both semi-dry desulfurization towers.
[0042] Referring to Figure 1, the first desulfurization device is communicated with a coal smoke pipeline for conveying coal smoke flue gas, the outlet of the first desulfurization device is communicated with the inlet of the first dust removal device, the outlet of the first dust removal device is communicated with the inlet of the CO removal device, the outlet of the CO removal device is communicated with one inlet of the flue gas mixing device, the inlet of the second desulfurization device is communicated with an empty smoke pipeline for conveying empty smoke flue gas, the outlet of the second desulfurization device is communicated with the inlet of the second dust removal device, the outlet of the second dust removal device is communicated with the other inlet of the flue gas mixing device, the outlet of the flue gas mixing device is communicated with the inlet of the ammonia injection device, the outlet of the ammonia injection device is communicated with the inlet of the SCR denitration device, the outlet of the SCR denitration device is communicated with the inlet of the waste heat recovery device, the outlet of the waste heat recovery device is communicated with the inlet of the induced draft device, and the outlet of the induced draft device is connected with the chimney pipeline.
[0043] Based on the above structural description, the embodiment is specifically described as follows:
[0044] Referring to Figure 1 , the arrow direction in the figure is the flow direction of the coal smoke flue gas, the empty smoke flue gas or the mixed flue gas. The coal smoke flue gas and the empty smoke flue gas drawn from the coal smoke side and the empty smoke side are conveyed through the coal smoke pipeline and the empty smoke pipeline respectively. The coal smoke flue gas enters the first desulfurization device, and in the embodiment, the desulfurization is performed by using a semi-dry desulfurization method, and soda ash or high-activity calcium hydroxide powder is used for desulfurization. The coal smoke flue gas after desulfurization enters the first dust removal device for dust removal. Similarly, the empty smoke flue gas enters the second desulfurization device, and the empty smoke flue gas after desulfurization enters the second dust removal device for dust removal.
[0045] The coal smoke flue gas after desulfurization and dust removal enters the CO removal device, and one or more layers of CO catalysts are arranged in the CO removal device. The mature CO catalysts at present use noble metals such as platinum, palladium and gold as active components, and are easily affected by SO2, H2O and NH3 in the heating furnace flue gas, resulting in poisoning and failure of the catalyst. The SO2 concentration in the coal smoke flue gas and the empty smoke flue gas is 50-300 mg / Nm 3 , in order to ensure the CO catalyst, the CO removal device is arranged after desulfurization and dust removal.
[0046] The CO in the coal smoke flue gas of 30000-50000 ppm is catalytically oxidized into CO2 under the action of the CO catalyst, and a large amount of heat is released. The catalytic oxidation of CO and oxygen to generate CO2 is an exothermic reaction in the catalytic oxidation reaction. The reaction equation is: 2CO + O2 = 2CO2. Under standard conditions, 1 mole of CO and oxygen catalytically oxidizes to generate CO2, which releases 92 kJ of heat. The catalytic oxidation reaction is to reduce the activation energy of the organic matter through the catalyst, so that it occurs at a lower temperature. Under the action of the catalyst, the activation energy of the reaction is reduced, the reaction rate is improved, and every 1000 mg / Nm 3 The oxidation of CO in the coal smoke flue gas of 30000-50000 ppm to CO2 can raise the temperature of the coal smoke flue gas by about 7.2℃. The oxidation of CO in the coal smoke flue gas of 30000-50000 ppm to CO2 can raise the temperature of the coal smoke flue gas by about 7.2℃.
[0047] After the CO is removed from the coal smoke flue gas, most of the CO is removed, and the temperature rises by 200-360℃. At this time, the temperature of the coal smoke flue gas reaches 300-500℃. The flue gas flowing out of the CO removal device is mixed with the flue gas after desulfurization and dust removal in the flue gas mixing device. The temperature of the mixed flue gas can reach 200-350℃. This temperature can reach the reaction temperature required by the catalyst in the SCR denitration device. An ammonia injection device is arranged between the flue gas mixing device and the SCR denitration device. After the mixed flue gas is injected with ammonia, it enters the SCR denitration device for denitration.
[0048] The temperature of the flue gas after denitration is 200-350℃. By arranging a waste heat recovery device, low-pressure steam or hot water is generated for heat recovery. The flue gas after waste heat recovery is discharged into the chimney through the induced draft device and finally discharged to the outside.
[0049] The heating furnace flue gas multi-pollutant co-processing system of the embodiment has the following advantages:
[0050] (1) The CO in the coal smoke flue gas is eliminated, and the problems of CO emission and explosion risk are solved.
[0051] (2) The coal smoke flue gas is raised in temperature due to the heat released during the CO removal process, and then mixed with the flue gas after desulfurization treatment in the flue gas mixing device. The overall temperature of the mixed flue gas will also rise, which can meet or partially meet the temperature required for subsequent denitration, reducing the problem of raising the temperature of the flue gas in the prior art to meet the denitration requirement, and reducing the operating cost.
[0052] (3) An ammonia injection device is arranged after the CO removal device, which reduces the influence of ammonia on the catalyst.
[0053] (4) Only one set of SCR denitration device, induced draft device and chimney are needed, so that the operation cost and large equipment investment of prior art can be saved, and the land area is reduced.
[0054] (5) GGH is not needed, so that the cost can be saved and the overall structure of the system is simplified.
[0055] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and the person skilled in the art can make a modification of the embodiments without creative contribution according to the need after reading the present specification, but as long as the present application is within the scope of the claims, it is protected by the patent law.
Claims
1. A multi-pollutant co-processing system for heating furnace flue gas, characterized in that, The device comprises a first desulfurization device, a second desulfurization device, a CO removal device, a flue gas mixing device and an SCR denitration device, the first desulfurization device, the CO removal device, the flue gas mixing device and the SCR denitration device are sequentially connected in pipeline along the flow direction of the coal flue gas, the gas inlet of the first desulfurization device is communicated with the coal flue pipeline for conveying the coal flue gas, the gas inlet of the second desulfurization device is communicated with the air flue pipeline for conveying the air flue gas, and the gas outlet of the second desulfurization device is communicated with the gas inlet of the flue gas mixing device.
2. The heating furnace flue gas multi-pollutant co-processing system according to claim 1, characterized in that, The device further comprises a first dust removal device and a second dust removal device, the first dust removal device is arranged between the first desulfurization device and the CO removal device, and the first desulfurization device, the first dust removal device and the CO removal device are sequentially connected in pipeline, and the second dust removal device is arranged between the second desulfurization device and the flue gas mixing device, and the second desulfurization device, the second dust removal device and the flue gas mixing device are sequentially connected in pipeline.
3. The heating furnace flue gas multi-pollutant co-processing system according to claim 2, characterized in that, The first dust removal device and the second dust removal device are bag dust collectors.
4. The heating furnace flue gas multi-pollutant co-processing system according to claim 1, characterized in that, The device further comprises an ammonia injection device, the ammonia injection device is arranged between the flue gas mixing device and the SCR denitration device, and the flue gas mixing device, the ammonia injection device and the SCR denitration device are sequentially connected in pipeline.
5. The heating furnace flue gas multi-pollutant co-processing system according to claim 1, characterized in that, The device further comprises a waste heat recovery device, and the gas inlet of the waste heat recovery device is communicated with the gas outlet of the SCR denitration device.
6. The heating furnace flue gas multi-pollutant co-processing system according to claim 5, characterized in that, The waste heat recovery device is a steam generator.
7. The heating furnace flue gas multi-pollutant co-processing system according to claim 1 or 5, characterized in that, The device further comprises an air induction device and a chimney, the gas outlet of the SCR denitration device or the waste heat recovery device is communicated with the gas inlet of the air induction device, the gas outlet of the air induction device is connected with the chimney in pipeline.
8. The heating furnace flue gas multi-pollutant co-processing system according to claim 1, characterized in that, The first desulfurization device and the second desulfurization device are semi-dry desulfurization towers.